长江三角洲地区生态资产评估

Evaluation and Change Analysis of Ecological Capital in the Yangtze River Delta Region

随着社会经济的高速发展,人们越来越关注自然资源的价值,生态环境的效益。评价生态系统的价值已经成为备受关注的焦点问题。利用遥感定量测量,采用Landsat-5卫星数据及其他辅助数据,结合生态学方法,对长江三角洲地区的4个省市1995年和2005年两年度的生态资产进行测量,并从生态资产分布格局、构成与变化格局、及其驱动因素进行分析。结果表明,该地区的生态资产分布很不均衡,从南向北逐渐递减。生态资产总量由1995年的5450.84×108元减少到2005年的4176.37×108元人民币,减少了23.38%。从生态资产构成来说,湿地和水体的生态资产减少的幅度最大,分别减少58.46%和34.44%,耕地、林地和灌丛的减少量也在20%左右。从生态资产变化格局来说,4省市生态资产减少量都在20%～30%之间,其中上海减少的程度更大,其次是江苏。生态资产减少的主要原因既包括自然因素的影响,也包括国家宏观指令和经济政策、经济发展、人口增长等人为因素的影响。

Along with socio-economic development, people are increasingly concerned with the value of natural resources and environmental benefits, with an emphasis on the assessment of ecosystem value. This paper proposes an applied evaluation model of ecological capital adapted from existing models. Landsat-5 satellite data along with some auxiliary data were used to assess the ecological capital of the Yangtze River Delta region for 1995 and 2005. The further analysis covered three aspects： the distribution of ecological capital, the composition and changing patterns of ecological capital, and the driving forces. The results show that the ecological capital of the Yangtze River Delta region is unevenly distributed, gradually decreasing from south to north. Higher values for ecological capital are found in the vegetated area of most parts of Zhejiang province and southern Anhui province, and the water-covered area in the Yangtze River, Huai River, Tai Lake and Cao Lake. Lower values for ecological capital are mainly found in and around Shanghai, and in parts of the Hangzhou Bay region. The ecological capital of Yangtze River region was reduced from 5 450.84 × 10^8 yuan in 1995 to 4 176.37 × 10^8 yuan in 2005, which was a decrease of 23.38 %. In the ten years of the study period, the ecological capital of wetland and water bodies had the largest reduction, respectively losing 58.46% and 34.44%, and farmland, forest and shrub-coppices also were reduced by about 20%, even grassland was reduced by 11.86%. Overall, the ecological capital reduction in the four provinces ranges from 20% to 30 %, with Shanghai reduced the most, followed by Jiangsu, Zhejiang and then Anhui. We classified the changing of ecological capital into five levels： sharp decline （ - 50% - - 100%）, moderate decline （ - 15% - - 50%）, approximately stable （ -15% - 15%）, moderate increase （15% -50%） and sharp increase （50% - 100%）. The ecological capital of the Yangtze River region as a whole is in decline, especially in Shanghai and the Hangzhou Bay region which declined sharply, mainly due to urban sprawl. Southwest Anhui province and south and west Zhejiang province sharply increased in ecological capital value due to improved forest cover. The driving reasons for the change in ecological capital include natural factors as well as anthropogenic factors, such as national planning and economic policies, economic development, and population growth.